A scientist loaned his Nobel Prize to an experiment on national television.

Professor Sir Harry Kroto, Emeritus Professor of Chemistry at the University of Sussex, was awarded the 1996 Nobel Prize in Chemistry for his research in the mid-1980s on a new form of carbon.

And Dr Peter Wothers, who was giving the 2012 Royal Institution Christmas Lectures, used Professor Kroto’s prize medal - made of solid 18-carat green gold and plated with 24-carat gold - to find out whether a member of the audience was really worth her weight in gold.

During the Royal Institution lecture, Dr Wothers and Professor Kroto also investigated, in the name of science, what happens when you set fire to a diamond.

The annual lecture series, filmed in front of a live audience of schoolchildren, is designed to present scientific subjects to a general audience in an informative and entertaining manner.

This year’s subject was the chemistry of the world around us: air, water and earth.